Washing Machine Plumbing Plumbing HelpPlumbing Help
Washing Machine Drain Connection. Regardless of whether you are installing a standpipe or a laundry tray to drain the washing machine, you will need to locate and tie into an existing gravity drainage system and vent the trap. Horizontal drains need to have a minimum grade of 1/4" per foot; Drain height for a laundry tray is 181/2" from the floor.